Standard porcelain toilet tanks may develop leaks due to improper float arm levels, worn ball cocks, corroded flappers or worn or deteriorated tank to bowl gaskets. Porcelain tanks may also crack or fracture due to defects, over tightened tank bolts, fatigue, vibrations or temperature changes. Such a crack can result in flooding of the premises with consequential damage significantly greater than the cost of the damage to the toilet.
It is known therefore to provide devices which time a period of flow of water to a device and shut off the flow when the flow continues after a required period of time.
Such a situation may occur in the event that the tank cracks. More commonly such an event occurs when the flapper valve leaks or sticks open. While the second event may not be catastrophic, if not properly monitored can lead to significant excess water usage.
A device of this type is particularly important in rental accommodations where the occupants may be less attentive to the operation of and costs associated with the devices in the accommodations and may therefore leave a toilet tank filling continuously, provided it operates when required.
A number of devices have been previously provided but many of these require a supply of electricity either from a main supply or a battery supply to provide actuation of electrical components such as timers and solenoid valves. Such devices are of course undesirable and it is much more suitable for an arrangement of this type to be operated solely by the hydraulic pressure and action of the water passing through the valve.